1. Technical Field
The present invention relates in general to communication connections that are performed across a communication line and, in particular, to increasing the efficiency with which communication connections are made across communication lines.
2. Description of the Related Art
Conventionally, when a user is trying to connect a personal computer (PC) to a communication network, if the user's attempt to access the network at an access point on the communication network is unsuccessful, he or she either waits for awhile and again tries to make connection at the same access point, or designates a replacement access point and tries to make a connection there. Various systems by which to make such a connection have been proposed. They can be roughly classified as follows:
(a) Auto-Redialing Method
An example redialing method is one whereby, when an attempt to make a connection using a registered dialing number fails, another attempt to make the connection is made using the same registered dialing number. Concerning this, disclosed in Japanese Unexamined Patent Publication No. Hei 6-233005 is a method by which a dialing command will be disregarded when the interval at which it is issued violates the rule that, to access the dialed line, the number of auto-redials that are made in three minutes shall be two or fewer, except in an emergency, such as when there is a fire or a burglary. For connection to another access point using the above-described auto-redialing method, the designation of a replacement access point is required.
(b) Dialing Method Involving the Alternate Use of a Dialing Number and a Replacement Dialing Number
According to this method, initially, a first (main) and a second (sub) address to be accessed are registered, and then an attempt to make a connection is made using the first address. If the attempt fails, an access attempt is then made using the second address. With this method, however, even though there is less probability that an access attempt using the first address will be successful than there is that one using the second address will be, the access attempt using the first address must be performed. As a result, a fast connection is not made, and the unnecessary transmission of a number to be dialed causes a busy condition at a telephone exchange.